I'm 5'4 140 lbs. Currently a 36DD. I'm going to be having a reduction. Would I look too small if I go down to a 36B?

It is difficult to evaluate and advise without any pictures,  I recommend you consult with a board certified PS for a much more detailed exam, best of luck!

Thank you for your question,     I strongly recommend you consider a larger cup size as going too small may jeopardize vascularity and wound healing. Women no longer need to undergo massive breast reduction in order to experience pain relief. Please consider The Bellesoma Method to alleviate pain from large breasts by transfering the weight of breast to the underlying chest muscles. This maneuver relieves the skin envelope in being the only structure holding breasts in place. With this particular technique, ducts are preserved along with nerve supply maintaining nipple sensation and the ability to breast feed.  The muscle acts as an active structure that easily maintains and lifts breasts long term. Attached is an example of a woman who wanted a lift without implants and without the ugly vertical incision. You are welcome to visit my gallery to see more examples.Best wishes, Dr. Gary Horndeski

It is very hard to reduce very large breasts to very small breasts without some loss of shape or risk of viability of the tissue or skin.

Thank you for the excellent question and congratulations on your decision to proceed with breast reduction surgery; this operation tends to be one of the most patient pleasing operations we perform.

 With the goal of improving communication with my patients I find the use of photographs of “goal” pictures (and breasts that are too big or too small) and computer imaging are very helpful. For example, I have found that the use of words such as  "proportionate” or “B cup” or "too small" means different things to different people and therefore prove unhelpful. Also, as you know, cup size varies depending on who makes the bra; therefore, discussing desired cup size may also be inaccurate. 

Once you have communicated your goals carefully, your plastic surgeon will be able to provide you with an estimation of how much tissue will need to be removed, in order to achieve your desired outcome.
Best wishes with your breast reduction procedure; hopefully you will be very pleased with the outcome of the procedure performed.

A drop from a DD to B may not be possible since some breast tissue needs to be left behind. Best to ask your plastic surgeons about what is realistic for you. See link below for examples.